Formula For Physics Flashcards
Velocity
Velocity=speed/time
What is acceleration
Rate of change in velocity
Equation for acceleration
Acceleration= change in velocity/time
What is acceleration measured
M/s2= metres per second/seconds
2nd formula for acceleration
2as= v2-u2
Gradient of distance/time graph shows?
The speed the object is travelling
What does the gradient of velocity time graph show
The acceleration or decelration of an object
On velocity of time graph how to find the distance
Area underneath the curve
What is a force
A force is a push or that acts upon an o as a result of that object’s interactions with its surroundings.
What is forced measured in and it sclar/vector
It is measured in newtons, and has both magnitude and direction
Contacts force and non contact force
Contact force can be only exerted when objects physically touch
Whats newton first law
A resultant force is required to change the motion of an object
Whats newton first law
A resultant force is required to change the motion of an object
Newton second law
A resultant force will cause an object to accelerate in the direction of the force.
What is the equation for force
Force=mass x acceleration
Bearings
A ‘bearing’ is an angle measured clockwise from the north direction.
For example, in the image above, the vector (the dark blue arrow) is at a bearing of 140°, because it’s 140° clockwise from north.
Formula for weight
Weight= mass x gravity
2 factors that dtermine the strength of gravitational force of attraction
Distance between objects
The mass of objects
Formuala for gravitational potential energy
Gravitational potential emergy=mass x gravity x height
Key points to understand objects undergoing circukar motioj
Key points to understand for objects undergoing circular motion:
The objects changes direction continuously, which changes it’s velocity
This change in velocity means the object accelerates
The acceleration is caused by a centripetal force acting inward
What is centripetal force dependent on and how
Mass:
Increasing the mass would increase the centripetal force required to keep the object travelling at the same speed with the same radius.
Speed:
Increasing the speed would increase the centripetal force required to keep the object travelling with the same radius and mass.
Orbital radius:
Increasing the radius of orbit would decrease the centripetal force required to keep the object travelling at the same speed.
Newtons third law
When two obejcts interact they are equal and opposite
Mometum formula and units
Momentum=mass x velocity
Kg m/s
P=mv
The conservation of momentum principle states:
The total momentum before the collision is equal to total momentum after the collision
Force to momentum equation
Force= change in momentum/velocity
F=^p/t
What is stopping distance and formula
‘Stopping distance’ is the total distance a car travels from the moment when the driver first notices an obstruction, to when the car stops.
Thinking distance + braking distance
A vehicle drives twice as fast what occurs to breaking distance
The breaking distance gets increased by 4 times
Name all energy stores
Thermal
Gravitational potential
Elastic potential
Magnetic
Chemical
Electrostatic
Nuclear
Kinetic
Way energy can be transferred
Mechanically
Electrically
Through heating
Via infrared radiation
Via light or sound waves
Open system
Can gain or lose energy to oustide world
What happens as an object falls
s an object falls, energy is transferred from its gravitational potential energy store, to its kinetic energy store.
Formula for kientci energy
Kinetic energy= 0.5 x mass x velocity2
E=0.5 x m x v2
Open vs closed system
An open system exchange energy and matter with its surroundings. A closed system exchange energy or matter with the surroundings.
Kinetic energy and gravitational potentisl energy
As an object rises, KE is converted to GPE
As an object falls, GPE is converted to KE
KE lost = GPE gained and KE gained = GPE lost
Gpe=maximum and KE=minimum
Formula for efficiency
Efficiency= useful energy output/ total energy output
Efficiency= useful power output/totalnpower output
Which of the following are features of a house which help to reduce heat loss by conduction?
Fouble galzed windows
Cavity walls
Walls made of a material with low thermal conductivity
Reducing friction
Fast moving vehicles like cars and planes have a streamlined shape to reduce friction from air resistance. This allows them to use less fuel.
Lubricants
Pros and cons of fossil fuels
Cheap, can be used in any conditions, current infrastructure requires fossil fuels
Limited resource
Produce carbon dioxide when burnt
Also produce toxic gases
Pros and cons of nuclear energy
Do not produce pollutants, can be used in any conditions, very unlikely to run out
Technically still finite
Radioactive waste which remians harmful for thousands of years
Expensive
Pros and cons of biofuels
They’re easy to transport
They’re renewable
They can be used in cars
They require a large areanof land to grow
They require a lot of energy to harvest,process and transport
Pros amd cons of solar and wind power
They don’t produce any pollutants while operating
They have low running costs
Take up a lot of land and space
Very dependent on weather so inconsistent
Hiave relatively high costs
Power dfenition
Power is the rate at which energy is transferred, or the rate at which work is done.
Power formula
P=w/t and p=e/t
